JPS59184838A - Dust measuring device of boiler or the like - Google Patents

Abstract

PURPOSE:To simplify an equipment by fetching a sampling gas of a dust measuring device by utilizing a differential pressure of an outlet side and an inlet side of an induced darft machine. CONSTITUTION:Air is sent to a boiler 3 by a forced draft machine 1, and the exhaust gas from the boiler 3 passes through ducts 4, 6, 8 and 10, an air preheater 5, a dust collector 7 and an induced draft machine 9, and is discharged from a chimney 11. In this case, a differential pressure is generated between the outlet side duct 10 of the draft machine 9 and the inlet side duct 8. Thereafter, a sampling branch pipe 20 is fetched from the duct 10, and a sample collecting device 21 is connected to the pipe 20. Subsequently, a flow rate measuring orifice 22 and a flow rate adjusting valve 23 are connected, and also a suction pipe 24 is connected. The pipe 24 is connected to the duct 8. Since sample gas is led in by utilizing a pressure difference by the draft machine 9, a special leading-in pump and its protective equipment become unnecessary, and the equipment is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a dust measuring device for a boiler or the like.

[Prior art]

FIG. 1 shows an outline of a conventional soot and dust measuring device of this type. In FIG. 1, air from a forced draft fan 1 is supplied to a boiler 3 through a duct 2, and exhaust gas from the boiler 3 is passed through ducts 4, 6, 8 and 10 respectively to an air preheater 5. Dust collector7. The dust is discharged from the chimney 11 through the induced draft fan 9, and in the exhaust gas system of the boiler 3, the soot and dust measuring device is connected to the dust collector 7.
A sampling branch pipe 12 is taken out from the duct 8 between the duct 8 and the induced draft fan 9, a sample collector 13 is connected to it, and an SOx absorber 14 is connected after the sample collector 13. Dryer 15. It is constructed by sequentially arranging a vacuum pump 16, a recycle regulating valve 1, a flow rate measuring orifice 18, and a flow meter 19 in parallel with the vacuum pump 16.

In this conventional configuration, a part of the exhaust gas that has passed through the dust collector 7 is sucked as a sample gas by the vacuum pump 16,
From this sample gas, dust is absorbed by the sample collector 13, and Sox is absorbed by the SOx absorber 14, which is dried by the dryer 15, passed through the vacuum pump 16, and then passed through the orifice. 18. The gas flows into the flow meter 19 and is discharged into the atmosphere. During this time, the flow rate is adjusted by controlling the opening of the recycle regulating valve 17 to recirculate the gas on the outlet side of the vacuum pump 16 to the inlet side.

In this conventional configuration, the SOX absorber 14 and the dryer 15 are provided mainly to protect the vacuum pump 16 and the flow meter 19, and their presence does not affect the equipment itself. This has the disadvantage of requiring a lot of equipment, making it complicated, and requiring a lot of time and effort for measurement.

[Summary of the invention]

In view of these conventional drawbacks, the present invention uses the differential pressure between the outlet side and the inlet side of an induced draft fan to collect sample gas, instead of the suction of a conventional vacuum pump.
With this vacuum pump.

By omitting the flowmeter, the SOx absorber and dryer to protect them, the equipment configuration and its handling are simplified, and by returning the sample gas after soot and dust absorption to the exhaust gas system, the surrounding area of the equipment can be reduced. It is designed to maintain cleanliness.

〔Example〕

Hereinafter, one embodiment of the dust measuring device according to the present invention will be described in detail with reference to FIG. 2.

The embodiment shown in FIG. 2 is a block diagram of an apparatus corresponding to the conventional example shown in FIG. In this FIG. 2, the same reference numerals as in FIG. 1 indicate the same or corresponding parts. A sample collector 21 is connected to the duct 10, and a flow rate measuring orifice 22 and a flow rate regulating valve 23 are sequentially arranged after the sample collector 21. is returned to the inlet side duct 8 of the induced draft fan 8 through a suction pipe 24.

That is, in this embodiment configuration, a part of the exhaust gas is taken out as a sampling gas to the sampling branch pipe 20 by the pressure on the outlet side of the induced draft fan 9, and the soot and dust is absorbed from the sampling gas into the sample collector 21. After measuring the flow rate using the flow rate measurement orifice 22 and adjusting the flow rate using the flow rate adjustment valve 23, the sampled gas is induced through the suction pipe 24, and the exhaust gas is extracted using the suction force on the inlet side of the ventilation fan 9. It is returned to the system. In this way, with this embodiment configuration, the differential pressure between the outlet side and the inlet side of the induced draft fan can be maintained without having a vacuum pump inside the device to actively take out the sample gas as in the conventional case. Take advantage of
Similarly, sample gas can be drawn in.

〔Effect of the invention〕

As described in detail above, according to the present invention, there is a device for extracting part of the exhaust gas from the exhaust gas system of a boiler as a sampling gas and measuring soot and dust, and the outlet side of the induced draft fan incorporated in the exhaust gas system. Since the differential pressure between the inlet side and the inlet side is used to take out the sampling gas and return the gas to the exhaust gas system after sample collection, there is no equipment in the measuring device for taking out the sample gas.
In this case, there is no need for a vacuum pump, so both these devices and the devices for their protection can be omitted.
Not only can the device configuration be simplified, but the labor of soot and dust measurement can also be sufficiently reduced, and the sample gas can be used directly after measurement.
Since it is returned to the exhaust gas system without being released into the atmosphere, the surrounding area can be kept clean and environmental pollution is not inevitable.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an overview of a conventional dust measuring device, and FIG. 2 is a block diagram showing an outline of a dust measuring device according to an embodiment of the present invention. 1... Forced draft fan, 3... Boiler, 5...
Air preheater, 7... Dust collector, 9... - induced draft fan, 11... Chimney, 20... Sampling branch pipe,
21... sample collector, 22 @... 1 flow rate measuring orifice, 23Φ... flow rate adjustment valve, 24... Φ suction pipe. Patent Applicant Mitsui Engineering & Shipbuilding Co., Ltd. Agent Kazutaka Yamakawa (and 1 other person)

Claims (1)

[Claims] In an exhaust gas system for a boiler, etc., in which exhaust gas from a boiler, etc. is guided from a dust collector to a chimney via an induced draft fan, the differential pressure between the outlet side and the inlet side of the induced draft fan is used to guide the exhaust gas from the outlet side. The boiler is characterized in that the gas is taken out as a sampling gas under flow rate control, soot is collected from the sampling gas into a sample collector, and the gas after the sample collection is returned to the inlet side. Soot and dust measurement equipment such as.